JPS6026633B2 - Abnormal approach detection and collision prevention device between torch and workpiece in automatic welding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an abnormal approach detection and collision prevention device between a torch and a workpiece in an automatic welding apparatus that performs automatic welding while controlling the relative positions of the workpiece and the torch by appropriate control means. .

The present applicant previously filed the following documents: Samurai Sekisho 54-15441 and Tokugansho 5
No. 4-64,853 presented an automatic welding device that uses the torch electrode itself as a sensor. In this automatic welding device, a welding voltage and a sensor voltage are selectively applied to the electrodes of the torch via a special voltage application means in response to a welding command or a sensor command from a control means as appropriate,
During sensing, the current state between the electrode and the workpiece is detected to find the weld line on the workpiece. The torch normally has a tip and a tip adapter attached to the torch body via an insulator, which guides the insertion of the electrode into the torch. Currently, the torch is formed into a long and narrow shape, and no insulator is provided near the tip of the torch, which becomes hot during welding.

Therefore, if the inside of the torch tip is clogged with spatter during automatic welding and the electrode and the torch body become incompatible, when the torch body and the workpiece come abnormally close during subsequent sensing operation, the situation will be as if the electrode and the workpiece were energized. , causing sensing errors. In addition, in the case of the aforementioned torch, some malfunction during automatic welding may cause the torch and/or
Or, when a workpiece runs out of control, there is no means to detect abnormal approach between the two and prevent a collision.

In view of the above-mentioned circumstances, the present invention attaches a conductor part to the outer surface of the torch main body via an insulating pair member, applies a detection voltage to the conductor member at all times during operation of an automatic welding device, and applies a detection voltage to the conductor member at all times during sensor and automatic welding. If the torch approaches the workpiece abnormally and a proximity discharge occurs between the conductive member and the workpiece, the current energization signal immediately stops the movement of the torch and/or the workpiece, and prevents the torch from approaching the workpiece abnormally. This product provides a device for detecting abnormal proximity between a torch and a workpiece in automatic welding equipment and for preventing collisions, with the aim of preventing accompanying sensing malfunctions and damage to the torch, etc. due to collisions between the torch and the workpiece. be.

The embodiment shown in the figure will be explained.

In FIG. 1, the automatic welding device 1 moves the workpiece fixture 2 that fixes the workpiece W in the left-right direction (hereinafter referred to as the "X-axis direction").
・It is movable in the front-back direction (hereinafter referred to as the "Y-mari direction") and rotatable in the horizontal direction (hereinafter referred to as the "R8-mari direction"), and the torch mount 4 of the torch 3 can be moved in the up-down direction (
It is configured to be movable in the "Z-axis direction" (hereinafter referred to as the "Z-axis direction") and swingable around the vertical axis L (hereinafter referred to as the "center axis direction"), and the movement and rocking position of the workpiece W and the torch 3 are controlled. A control means 5 is provided for controlling.

Reference numeral 6 denotes a base having an L-shape in plan view, and a first frame 7 is fixed on one side.

Reference numeral 8 denotes a trolley thinly mounted on the first frame 7, which is driven by a suitable speed reducer and a forward/reverse motor with a brake (not shown), and is connected to the X-axis via a suitable transmission means (not shown) such as a ball screw. It is designed so that it can move in any direction.

Reference numeral 9 denotes a second frame body iron-mounted on the truck 8, which is movable in the Y-axis direction by the same drive and transmission means as the truck 8, and the front end of the second frame body 9 has a The aforementioned workpiece fixture 2 is rotatably attached.

10 is a vertical frame erected on the other side of the L shape of the base 6;
The aforementioned torch fixture 4 is attached to the distal end of the horizontal arm 11 so as to be movable in the Z-axis direction so as to be swingable in the axial direction.

The drive means for the horizontal arm 11 and the torch mount 4 are both forward/reverse motors with brakes (not shown). The torch 3 is arranged so that the welding point WP on the extension of the central axis M (this point is a virtual point and does not always coincide with the tip of the electrode W) is always on the vertical axis L. It is attached to the tip of the torch mount 4, and its mounting angle, that is, the angle Q formed by the center axis M with respect to the vertical axis L, depends on the welding mode to be performed (butt welding, fillet welding, etc.) and the workpiece W. The angle is determined as appropriate depending on the shape of the angle, but it is usually around 45 degrees except in special cases.

12 is a power supply device for applying voltage and supplying current to the electrode W etc. of the torch 3; 13 and 14 are an electrode supply roll and a pair of turtle pole feeding rollers attached to the power supply device 12, respectively; W is a variable speed motor 15 (third
The torch is pulled out from the supply roll 13 by the rotation of the pre-conveyance roller 14, which is drive-controlled by the FIG. 3.

Reference numeral 17 denotes a welding control instrument derived from the power supply device 12 and attached to the control means 5.

Reference numeral 18 denotes a remote control panel, which remotely controls the movement and rotation of the various parts by manual operation, and inputs a user program into the memory (not shown) in the control means 5 based on the remote control. be.

FIG. 2 is a longitudinal cross-sectional view showing details of the torch 3, which includes a hollow cylindrical main body 101 that is elongated and has a slightly larger diameter only at the base end, and a cap attached to the base end of the main body 101. A socket 102, an insulating sleeve 103 for receiving an electrode W formed in the center of the socket 102, and the main body 1.
A cylindrical insulating material 104 with an open end is attached to the inward protrusion of the sleeve 103 so as to cover the inner surface of the socket 102 and the inner surface of the socket 102, and A chip adapter 05 attached to the tip of the protruding portion, and a chip 106 attached to the tip of the tip adapter 105 and extending to near the tip of the main body 101 to maintain an appropriate gap between it and the inner surface of the main body 101. consisting of the flexible tube 16
The electrode W passes through the insulating sleeve IJ tube 103, the tip adapter 105, and the tip 106, and protrudes an appropriate amount toward the tip of the torch 3. Further, the torch 3 has a main body 10
A conductor member 108 for detecting abnormal proximity between the torch 3 and the workpiece W is attached across the entire circumference of the outer surface of the torch 3 via an insulator member 107.

FIG. 3 is a schematic explanatory diagram mainly showing a circuit block diagram of the power supply device 12. As shown in FIG.

In FIG. 3, reference numerals 201 and 202 are a voltage applying means and an energization state detecting means built into the power supply device 12. Of these, the voltage applying means 201 includes a welding power source 201a, a sensor power source 201b, and an abnormal approach detection power source. 201c, a switch 201d that connects one end to the electrode W and selectively connects it to either the welding power source 201a or the sensor power source 201b as appropriate; one end of the switch 201d connects to the electrode W;
It consists of a normally closed open/close switch 201e, etc., which is connected to the abnormal approach detection power source 201c at appropriate times. The energization state detection means 202 is a sensor whose one end is connected to a sensor power source 201b and an abnormal approach detection foot source 201c, and whose other ends are both connected to the workpiece W together with the opposite switch 201d side of the welding power source 201a. Energization state detection circuits 202a and 202b for use and abnormal approach detection, and each of the above-mentioned energization state detection circuits 202a and 202, respectively.
It consists of energization state detection output circuits 202c and 202d for a sensor for inputting a change in the energization state (current, voltage, or a change in both) at b as a detection signal and transmitting it to the control means 5, and for abnormal approach detection.

When operating the automatic welding device, such as during sensing and automatic welding, or when manually moving the torch 3 or workpiece W, the open/close switch 201 is always turned on.
e is closed, and an abnormality nearness detection voltage (this is high voltage and low current at the same level as the sensor voltage) is applied to the conductor member 108 of the torch 3.

In this way, when the torch 3 abnormally approaches the protrusion W of the workpiece W during the above-mentioned sensing, automatic welding, or manual assistance, the conductor section 108 and the protrusion W of the workpiece are energized and discharged. , a change in voltage and/or current is detected by the energization state detection circuit 202b, and the energization state detection output circuit 202d issues a signal of "energization" to the control means 5, and the control means 5 receives this signal and operates the automatic welding apparatus. A command to stop driving is issued to each drive source.

As a result, the movement of the torch 3 and/or the workpiece W is immediately stopped, and a collision between the torch 3 and the workpiece W is instantly avoided. In the above-mentioned embodiment, the power supplies 201b and 201c for the sensor and abnormal approach detection were provided separately, but a single power supply is used for these, and the internal circuit of this power supply connects the circuit leading to the electrode W and the torch 3. Conductor member 1
It is also possible to implement it by completely separating the circuit leading to 08.

It is also possible to connect the output side of the energization state detection output circuit 202d to a separately provided alarm to issue an alarm when the torch 3 and the work W approach abnormally.

As detailed above, <when using the present invention apparatus, a conductor member is attached to the outer surface of the torch body via an insulator section,
Since a detection voltage is always applied to the conductive member while the automatic welding equipment is in operation, if the torch approaches the workpiece abnormally during sensing, automatic welding, or manual operation, this can be detected. It is possible to emergency stop the movement of the torch and/or the workpiece, and avoid collisions between the torch and the workpiece.

In addition, since the energization state detection circuits for the electrode/workpiece and the torch conductive member/workpiece are provided separately, even if sensing is performed without realizing that spatter is stuck between the torch body and the chip, the torch and workpiece can be easily detected. By adding simple components to conventionally known torches, we can prevent abnormal approaches from being mistakenly detected as energization between the electrode and workpiece.
The safety and reliability of automatic welding equipment could be significantly improved by simply making some additions and changes to the power supply circuit.

[Brief explanation of the drawing]

Fig. 1 is an overall perspective view of an automatic welding device as an example employing the device of the present invention, Fig. 2 is an enlarged vertical sectional view of a torch, and Fig. 3
The figure is a schematic explanatory diagram mainly showing the circuit configuration of the power supply device. In the figure, 1 is an automatic welding device, 3 is a torch, 5 is a control means,
12 is a power supply device, 101 is a main body of the torch 3, 107 is an insulator member, 108 is a conductor member, and W is an electrode. O 2 Box O Prisoner O 3 Diagram

Claims (1)

[Claims] 1. In a device that automatically welds a torch and a workpiece while controlling their relative positions by appropriate control means, an insulator member attached to the outer surface of the main body of the torch, and an insulator member attached to the outer surface of the insulator member. a conductor member, a means for applying a detection voltage to the conductor member in accordance with a command from the control means, and a means for detecting an energization state of the conductor member, and the control means detects a voltage from the energization state detection means. of"
1. An abnormal approach detection and collision prevention device between a torch and a workpiece in an automatic welding apparatus, characterized in that the movement of the torch and/or the workpiece is stopped upon receiving an energization signal.